Installing new controller cards

In a PC running SuSE Linux 8.1, the FireWire controller was moved to a different internal pci slot and a new USB2 controller inserted. Linux does not recognise the new card/s. Re-booting the PC should have done the trick but not in this case. What steps or procedures have to be followed so that Linux recognises the new cards? The PC is HP Pavilion running SuSE 8.1. There are 4 USB 1.1 slots built into the PC. As mentioned elsewhere, a USB hard drive has to be connedted to the PC. Hence the need for a USB2 card. Connecting the drive to existing USB 1.1 is successful as Linux recognises the drive and attaches it to /dev/sda1. Any help appreciated.